Electronic device in which maximum number of mountable printed circuit boards is changeable

Abstract

An electronic device includes a slot, and a backboard that is disposed on the depth side in the slot and is electrically connected to a printed circuit board inserted in the slot. The electronic device further includes a casing having the slot formed therein, the casing being configured to accommodate therein at least part of the backboard, and a cover member configured to be attachable to and removable from the casing. When attached to the casing, the cover member together with the casing forms the external appearance of the electronic device. The cover member is attached to the backboard integrally.

What is claimed is: 
     
       1. An electronic device comprising:
 a slot; 
 a backboard that is disposed on a depth side of the slot and is electrically connected to a printed circuit board inserted in the slot; 
 a casing having the slot formed therein, the casing being configured to accommodate therein at least a part of the backboard; and 
 a cover member configured to be attachable to and removable from the casing, wherein the backboard is integrally attached to the cover member and unattached to the casing such that the backboard and the cover member are removable from the casing together as one unit upon removing the cover member from the casing in a direction parallel with a plane defined by the backboard, wherein when attached to the casing, the cover member together with the casing forms an external appearance of the electronic device, 
 wherein the cover member is formed with an expansion slot in which an expansion printed circuit board is inserted, the expansion printed circuit board being different from the printed circuit board inserted in the slot of the casing. 
 
     
     
       2. The electronic device according to  claim 1 ,
 wherein the backboard includes:
 a first connector configured to be electrically connected to the printed circuit board; and 
 a second connector configured to be electrically connected to the expansion printed circuit board, 
 
 the second connector is disposed in a part of the backboard that is not accommodated in the casing, and 
 the cover member covers the part of the backboard not accommodated in the casing and the expansion printed circuit board connected to the backboard. 
 
     
     
       3. The electronic device according to  claim 2 , wherein the backboard comprises a plurality of backboards having different numbers of the second connectors, and the backboards are selectively mounted to the casing. 
     
     
       4. The electronic device according to  claim 2 , wherein the expansion slot is configured to guide the expansion printed circuit board to the second connector. 
     
     
       5. An electronic device comprising:
 a casing having a slot formed therein; 
 a backboard that is disposed on a depth side of the slot in the casing and is electrically connected to a printed circuit board inserted in the slot; 
 an expansion backboard; 
 an expansion printed circuit board different from the printed circuit board inserted in the slot, the expansion printed circuit board being electrically connected to the expansion backboard; 
 a connector attached to a surface side of the casing so that the expansion backboard is electrically connected to the backboard through the connector; and 
 an expansion cover member attached to the expansion backboard, wherein the expansion cover member covers the surface side of the casing, the expansion backboard, and the expansion printed circuit board, wherein the expansion cover member and the surface side of the casing define an expansion slot therebetween configured for receipt of the expansion printed circuit board in a direction parallel with an insertion direction of the printed circuit board into the slot of the casing. 
 
     
     
       6. The electronic device according to  claim 5 , wherein the expansion backboard or the expansion cover member that is attached to the expansion backboard is provided with another connector.